what is the inside scoop on big Baltimore bridge crash?

Yep, economics (and therefore politics) drive port selection. Nothing to do with engineering except how much cheaper port facilities make shipping costs. The whole reason why the C&O and B&O transport systems where built and exist.

 

Gonzo , in Alabama every bridge is inspected yearly or bi-yearly based on a rating , we did some referb work on one to bring it up to a rating that let the State inspect it bi-yearly , we didn't fix everything , just what was known and what we saw , until their money ran out . Some of the work was to drill holes to stop cracks the State had been watching for some years , we couldn't figure out what would have caused them . But we came to a span that had four 50 ton jacks banded together that had been left under the bridge so long that the 4x12,s that they sit on had rotted . I told the inspector to see if they belonged to the company that had built the bridge 35 yr,s earlier , if so I had dib,s on them , but they had State #,s on them . We called the State and they said they didn't belong to them , we called a 2nd time and they said , they knew they were there , probably still there today . They had been lifting up one corner of a bridge span at a time to replace bearing pads , wonder how the cracks got there ? Everything is not inspected or caught when a bridge is inspected , they also already knew they had a problem on the bridge in Mississippi and put it on the list to be fixed , just like all the other problems they find during an inspection , no need to pay for another sonar , and no money to fix everything .

 

I am a bridge inspector and can simpatize with you.

 

That bridge that fell in Minnesota and killed 13 souls…everytime I drove over it, the damned thing was in a harmonic. Seemed predictably bad. Thread drift. Wonder if they got any bridge off the boat, yet.

 

They are about to start soon..
MSN https://www.msn.com/en-us/news/us/crews-turn-sights-to-removing-debris-from-ship-s-deck-in-baltimore-bridge-collapse-cleanup/ar-AA1nk6QW?ocid=msedgntp&pc=HCTS&cvid=feb4d71b23d846 91e272b13f45721d7c&ei=15

 

I think the Minnesota bridge fell from replacing a piece that was 3/4" with a piece 1/2" , and it,s start time will tell you about when the Baltimore bridge will be rebuilt .

 

You can read the NTSB report on that failure. I had nothing to do with harmonics. There were undersized gussets and there was excess construction weight added. That failure was caused by a design error.

 

I read the report.

I said I hated going over the bridge because it was always in harmonic motion, and not a little bit. When I’d drive over it, I’d seriously wonder if harmonics can result in metal fatigue. You know, how we get a pop top off a can? Not trying to discount the 1/2” gussets issue. I just found it to be the only bridge in a 0.25 second to 1 second vibration period and very off putting.

It was best described as a pretty shaky bridge.

 

When the cable stays on a bridge I worked on were being grouted , holes were drilled toward the base where there was a lap in the stay,s . When a cloud moved in front of the sun the stays would move 6" + or - in a minuet and screw up the hole alignment . All bridges and buildings move , the bigger or higher they are the more you feel it , and the more put off by it your are . I did an almost eyeball shaped high rise once that was 150 sqft shy of an acre of concrete with no expansion joint that had much more movement and cracking than I was comfortable with . The Engineer explained the movement of the building and educated me on round buildings , and I felt better . He was also uncomfortable with some of the cracking in some walls and told me to add rebar , I told him I already had , he told me to use a a 5000 mix concrete , I told him I already had , I told him to put expansion joints in the next buildings , and he did . fallguy ,When you move to Texas , if you decide to buy a condo get one in the 2nd phase of a development , they tend to fix most of the problems from the 1st phase . Also don't buy in a building that has X braces in the stairwell or any other place . Years after the cable stay bridge was built the state had to replace the grout in the cable stays because it had cracked , there are now shock,s attached to the base of the stays .

 

Not sure this is relevant, but a geotechnical engineer discusses refloating the MV Dali (the ship that took down the bridge) at:

www.youtube.com/watch?v=nB2fpBNPbjw

He admits he doesn't know much about ships. He very roughly calculates the forces involved in removing it from the sediment, and putting it back into the deepwater channel.

There are a lot of interesting comments on the video too. Not everyone agrees with that engineer.

It is interesting that while the MV Dali was damaged, so much of it remains intact. It isn't just a very big, heavy object, especially with its cargo; it must also be very strongly built.

I wonder if anything about building container ships will be learned from this incident. E.g., is there an economically practical way to get emergency power for steering back on faster?

Does it actually make sense for the people supplying the cargo to share in the costs related to the accident? Does similar legal rules apply to land and air transportation accidents too?

 

It think general average only applies to some of the liability issues. It applies to everything to do with the boat and the boats crew and it's salvage and return to service, but I don't think it applies to the bridge. Could be wrong. Sal Mercogliano did a second interview with Bill Doyle, the former port director and now CEO of one of the salvors, and he talked about it and gave the litany of what the different liabilities were to the various parties. I'll see if I can dig it up again.

But it's an odd law. It's not like everyone that ever drove over the bridge is going be made to chip in to rebuild it.

 

If I ship a non-hazardous package via Parcel Post or UPS, and the shipping truck has an accident, I sure hope I wouldn't be responsible for damage to the driver or truck...

(Of course if my package contained unlabeled hazardous materials that caused problems during the crash, I would expect to be liable. But that's a separate issue.)

 

You now have to sign that agreement when you hand the package over to the past office. You're liable for any damages your package causes.

-Will

 

Yes, but in this case, it's not the packages (specifically the containers) that caused the damage. I don't get why I would have any liability if my package didn't cause the damage - because the damage was caused by the shipping company(s).

 

Found this in today's BBC:

Baltimore sues owner and manager of 'unseaworthy' Dali over bridge collapse https://www.bbc.com/news/world-us-canada-68883659